As the use of network-based publication systems and marketplaces, such as on-line commerce services or auction services expands, and the volume of item listings in such applications increases, the speed, ease, and convenience with which information can be retrieved from such marketplaces increases in importance to customers.
Item listings in such network-based marketplaces typically include details of a particular item which is, for example, up for sale or auction. These details are typically stored in text format and include a description of the item together with other information, such as the price, useful to a potential buyer in assessing the item listing. In addition, item listings often include visual material related to the item, typically in the form of a photograph, drawings, or video clips.
The use of images in this context has customarily been limited to the provision of information about item listings to customers, but it would be useful to employ images associated with item listings for additional purposes, such as for image-based searching or for the automatic identification of images for fraud protection purposes.